High Strength Ta2C-Based Compounds for UHT Boost Nozzle Applications

Future generation propellants earmarked for DoD and MDA boost vehicles will create increasingly severe conditions (temperature, pressure and particle impingement) in the nozzle region that will prevent state of the art materials and designs from achieving the performance levels and costs being targeted for next-generation solid rocket motors. The demonstration of zero or near-zero erosion in the throat area is a much sought after goal for boost propulsion systems, since it offers direct payoff potential with respect to increased motor performance, reduced nozzle weight and lowered cost relative to current-generation of high performance rocket motors. For this Phase 1 STTR effort, the materials we propose for examination are based on high strength, high purity di-tantalum carbide (Ta2C) compositions and variants thereof. These ultrahigh temperature Ta2C-based materials will be fabricated by novel isostatic densification methods Exothermics has developed over the past few years. Due to their extremely high melting points, unique microstructures, and predicted stability against aluminized propellant exposure, we anticipate that such Ta2C-based compositions will be able to withstand 3000 - 3500°C propellant flame temperatures. The principal markets that would benefit from the availability of such ultrahigh temperature materials are in the MDA and DoD boost nozzle realm.